Power converters which have an inverter circuit including a plurality of switching elements, and a switching control section for controlling the actuation of the switching elements have been known. Such power converters are widely used, for example, in household electric appliances and industrial equipment in which the number of revolutions and the torque of the motor need to be controlled.
In the power converters, in general, a freewheeling diode is connected in antiparallel to each of the switching elements. Due to on-state voltage drop at a time when a current flows in the switching elements and the freewheeling diodes, the actual output voltage differs from the voltage instructed. Accordingly, the output current and the torque may be distorted.
To solve this problem, a method of determining a voltage instruction of the inverter in consideration of an on-state voltage drop of the device is shown, for example, in Patent Document 1. In Patent Document 1, the on-state voltage drop is compensated by considering the effect of dead time, too, which is set so that a pair of switching elements connected together in series in the inverter circuit will not be turned on simultaneously.